// 小鸟类
import {Sprite} from "../base/Sprite.js";

export class Birds extends Sprite{
    constructor() {
        const image=Sprite.getImage("birds");
        super(image,0,0,image.width,image.height,0,0,image.width,image.height);
        this.clippingX=[9,9+34+18,9+34+18+34+18];
        this.clippingY=[10,10,10];
        this.clippingWidth=[34,34,34];
        this.clippingHeight=[24,24,24];
        const birdX=window.innerWidth/4;
        const birdY=window.innerHeight/2;
        this.birdsX=[birdX,birdX,birdX];
        this.birdsY=[birdY,birdY,birdY];
        const birdWidth=34;
        const birdHeight=24;
        this.birdsWidth=[birdWidth,birdWidth,birdWidth];
        this.birdsHeight=[birdHeight,birdHeight,birdHeight];
        this.y=[birdY,birdY,birdY];
        this.index=0;this.count=0;this.time=0;
    }
    draw(){
        const speed=0.2;
        this.count+=speed;
        if(this.index>=2) this.count=0;
        this.index=Math.floor(this.count);
        const g=0.98/2.4;
        const offsetUp=30;
        const offsetY=(g*this.time*(this.time-offsetUp))/2;
        for(let i=0;i<=2;i++){
            this.birdsY[i]=this.y[i]+offsetY;
        }
        this.time++;
        super.draw(
            this.img,this.clippingX[this.index],this.clippingY[this.index],this.clippingWidth[this.index],this.clippingHeight[this.index],
            this.birdsX[this.index],this.birdsY[this.index],this.birdsWidth[this.index],this.birdsHeight[this.index]
        );
    }
}